Lightning-arrester.



No. 649,388. Patented May 8, I900.

A. J. WUBTS.

LIGHTNING ABRESTER. (Application filed. June 8', 1899.) (No Model.)

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ALEXANDER JAY VVURTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THEIVESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF PENNSYLVANIA.

LlGHTNlNG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 649,388, dated May 8,1900.

Application filed June 8, 1899- Serial N- 719 806| (N0 model.)

T all 7 711 it may OOH 061%: tures of my invention, which will behereinaf- Be it known that I, ALEXANDER J AY WURTs, ter more fully setforth. a citizen of the United States, residing at Pitts- In theaccompanying drawings, Figure 1 is burg, in the county of Allegheny andState of a perspective view of the operative portions 5 5 5Pennsylvania, have invented a new and useful of a single-polelightning-arrester embodying Improvement in Lightning-Arresters, (Casemy invention, and Fig. 2 is another perspec- No. 838,) of which thefollowing is a specificative view of the same device with one of thetion. cover-plates displaced from its operative po My invention relatesto that class of devices sition. Fig. 3 is a side elevation of one ofthe 6o [0 known as lightning-arresters that are emresistance-rods, aportion of its sheath being ployed for protecting electrical machinesand broken away. circuits from injury by charges of static elec-Referring now to the details of constructricity derived from theatmosphere. tion, 1 is a base-plate of any suitable form and The objectof my invention is to provide a material for supporting the operativeparts I 5 lightning-arrester which shall operate elfectof thelightning-arrester and provided with ively to relieve an electriccircuit of its static openings or screw-holes for attaching it to acharge and at the same time be free from any casing or othersupporting-base. Mounted danger of short circuits or otherdisarrangeupon the plate 1 or upon suitable blocks 2, ment due tocontinued service. fastened to said plate or formed integral 7o 20 Mypresent invention is an improvement therewith, are the operative partsof the lightupon the lightning-arrester covered by my ning-arrester,which will now be described. prior patents, No. 509,784, of November 28,3 is a block of non-conducting material, 1893, and No. 532,354, ofJanuary 8, 1895. preferably of wood, provided approximately It has beenfound in practice in some inmidway of its ends and at each side with a25 stances that after a considerable period of plate or strip 4, thisplate or strip also be service the conducting-paths between the ingpreferably of some hard wood arranged sparking-terminals or one or moreof such with its fibers substantially perpendicular to paths increase inconductivity to such an eX- the faces of the block 3, substantially asset tent that a short circuit is established, which forth in my PatentNo. 532,354. Set into each o renders the device substantiallyinoperative face or side of the block 3 adjacent to the for the purposeintended. It is for the purstrip 4is a sparking-terminal plate 5, ofbrass pose of guarding against the breaking down or other suitablemetal, the two plates 5 beof the arrester in this particular that I haveing electrically connected to one of the leads devised the improvementforming the sub- 6 for connection either to one side of the cir- 3 5ject-matter of this application. Ihave found cuit to be protected or tothe ground. Each by experiment that if there be a plurality of face orside of the block 3 is also provided spark-gaps the discharge instead ofdividing with a plurality of metal strips 7, four of these among theseveral gaps will almost invari strips being shown in each face, theinner ably pass at one gap only; but if a resistance ends of whichterminate at the adjacent side 40 be interposed in each path, all of theresistof the strip 4. A shallow charred groove 8 ances beingsubstantially equal, the discharge is preferably provided in each strip4 between will invariably subdivide, thus dividing the each of thesparking-terminals 7 and the corintensity of the entire discharge by thenu mresponding sparking-terminal 5. The funcber of paths. By thuspresenting a plurality tion of these charred grooves is fully set forth5 of paths for the static discharges and interin my prior patents,hereinbefore referred to. posinga suitable resistance in each path I amThe resistance interposed in the circuit is enabled to reduce the widthof the spark-gaps in the form of rods 0 of a suitable composimuch belowwhat was possible with the form tion for providing the amount andcharacter of arrester heretofore employed by me. of resistance desired,there being one rod for 50 The type of resistance device and themetheach sparking-terminal strip 7. The ends of 0d of its constructionconstitute other feathese rods are seated in metal sockets 10 and 11,the sides of which are split, so that they can be pressed into closecontact with the rods. The sockets 10 are either formed integral withthe strips 7 or so soldered or brazed thereto as to constitute in effecta continuation thereof. The sockets 11 are joined to a conducting-lead12, designed for connection with either one side of a circuit to beprotected or with the ground. Closely and securely fastened to each sideof the portion of the arrester thus far described by means of screws orsimilar means is a plate 13, provided with a transverse grooved strip14: in position to engage with the strip 4. This strip 14 and its groovecorrespond to the similar parts shown and described in my Patent No.532,354, already referred to.

I have found that a desirable material for the resistance-rods 0consists of a mixture of graphite, kaolin, and some binding inaterialsuch, for example, as starch. While rods formed of this mixtureare sufficiently strong and durable for transportation and ordinaryusage when thoroughly baked, I have found that they are much betteradapted for use in the relations here shown and described if they aremerely compressed and allowed to dry at ordinary temperatures. Undersuch circumstances the rods are fragile and will not withstandtransportation and ordinary handling without breakage to a greater orless extent. I therefore propose to provide each rod with astiffening-sheath 9, which extends either throughout the whole or thegreater portion of its length. ent purpose I leave the extreme ends ofthe rods unprotected in order that they may be inserted into theterminal sockets 110 and 11.

While stiffening-sheaths ofanysnitable material may be employed, I havefound that tough paper is well adapted for this purpose, and in order toapply it I moisten it until it becomes pliable, allowing it to partiallydry out, if necessary, then apply a coat of shellac or other adhesivematerial to the surface of the rod, then wind on a layer of paper and,if more than one layer is desired, apply to that layer another coatingof shellac or other adhesive material and over that wind the sec- 0ndlayer. This may be repeated until the thickness of sheath desired isobtained, when the last coating of paper maybe covered with a coating ofshellac.

For my pres- It will be understood that the number of coats of paper orother stiffening material and shellac or its equivalent may be anythingdesired, and I therefore do not limit myself in this regard.

The particular form and arrangement of parts shown in the drawings areemployed in order to provide an arr-ester of large capacity which shalloccupy a minimum amount of space. The duplication of sparking-termiualsand sets of resistance-rods not essential, however. I desire it also tobe understood that the composition and the form and dimensions of theresistance-pieces may be different from what is here specifically setforth, though I have found the form illustrated in the drawings and thecomposition specified to be admirably adapted for the rela* tions inwhich the resistance-pieces are used.

I claim as my invention 1. A lightning-arrester comprising a base blockof non-conducting material, a terminal plate embedded therein, aplurality of terminal strips also embedded in said base-block andseverally separated from the terminal plate by spark-gaps and aplurality of resists ance-rodshavingtheirinnerendsrespectively connectedto the outer ends of the terminal strips and their outer ends joined toa circuitterminal.

2. A lightning-arrester comprising a baseblock provided with a terminalplate and with a plurality of strips the inner ends of which areseparated from the inner edge of said plate by spark-gaps, acoveringblock for said plates and strips and a pluralityofresistancerods the inner ends of which are severally connected to theouter ends of the strips and the outer ends of which are connected to acircuit-- terminal.

.3. A lightningarrester comprising a pair of sparking-terminals at leastone of which is subdivided, a block in which said terminals are embeddedand a plurality of resistancepieces severally connected in series withthe terminal-subdivisions.

In testimony whereof I have hereunto subscribed my name this (Jth day ofJune, 1899.

ALEXANDER JAY Wlllt'lS. \Vitnesses:

Wnsnny G. CARR, ll. (1. 'luNnn.

